[74.03] Pulsar radio emission mechanisms.

M. Lyutikov (Caltech)

The theory of the cyclotron-Cherenkov resonance in the pulsar
magnetosphere is capable of explaining the main observational
characteristics of pulsar radio emission. The maser-type
instability is due to the interaction of the fast particles of
the primary beam and from the tail of the distribution
with the normal modes of a strongly magnetized one-dimensional
electron-positron plasma at the anomalous Doppler resonance
ømega(k)- k _II V_II + ømega_B/\gamma_res=0.
In the emission process a resonant particle emits a wave
undergoing transition to a higher rotational state
producing coherent emission in core-like pattern.
The conditions for the development of the cyclotron-Cherenkov
instability are satisfied for the both typical and millisecond
pulsars provided that the streaming energy of the bulk
plasma is not very high \gamma_p = 5\div 10 or the
relative streaming velocity of the electrons and positrons
of bulk plasma is nonvanishing. In a curved magnetic field
an instability at a drift-Cherenkov resonance
ømega(k)- k _II V_II- k _\perp\, U_d may also produce
a cone-like emission pattern.